CN116614078A - Photovoltaic module and junction box for photovoltaic module - Google Patents

Abstract

The application relates to a photovoltaic module (1) having at least two cell arrangements, which are externally accessible at connection contacts (4), the connection contacts (4) being arranged along a line on the back side of the photovoltaic module (1) to be assigned to groups of the cell arrangements, each group having two connection contacts (4). The photovoltaic module (1) is characterized in that exactly one junction box (11) is arranged on the rear side (3) of the photovoltaic module (1), which junction box has a housing (111) with at least one opening for passing through the connection contacts (4) towards the rear side (3), wherein the housing (111) covers all the connection contacts (4) of the photovoltaic module (1). The application also relates to a junction box (11) for such a photovoltaic module (1), wherein the housing (111) has an elongated basic shape, wherein all connection contacts (4) are arranged in a line along the longitudinal direction of the housing (111).

Description

Photovoltaic module and junction box for photovoltaic module

Technical Field

The application relates to a photovoltaic module having at least two cell units (Zellanoddnung) which are externally accessible at connection contacts which are arranged along a line on the rear side of the photovoltaic module in groups assigned to the cell units, two connection contacts per group. The application also relates to a junction box for such a photovoltaic module, wherein the junction box has a housing with at least one opening for passing through a connection contact, and wherein at least four contacts for contacting the connection contact are arranged in the housing.

Background

Photovoltaic modules, also referred to below simply as PV modules, for example for installation in rooftops or open air installations, generally have a plurality of photovoltaic cells (PV cells) which are connected in series and/or in parallel to form at least one cell arrangement which is accessible from the outside via a wiring cable. PV modules typically have a plurality of such cell arrangements connected in series within the PV module. In this case, each cell unit is usually led out of the module with its terminal connections, in order to switch on a so-called "bypass diode" in parallel with each cell unit. The bypass diode directs current around the shielded or faulty cell device. Without the bypass diode, a shadowing or failure of one of the cell devices of a module will also reduce the current flowing through the entire module even if the other cell devices of that module or the other modules in series with that module are not shadowed or have no failure.

PV modules are known from the prior art, in which connection contacts of existing cell arrangements (typically three cell arrangements) are accessible adjacent to one another on the rear side of the PV module in a common connection region.

For example, in document US 2016/0141435 A1 a PV module with such a wiring device is described in an embodiment. In another embodiment, the document describes a PV module in which the contact faces of different cell arrangements are not located in one common connection area on the back side of the PV module, but at a plurality of different locations. This design of the PV module is particularly suitable in particular if the PV module has two parallel rows of PV cells (so-called strings) on every two connection contacts. By positioning the common connection contacts along a central line extending centrally with respect to the longitudinal extension direction of the PV module and thus parallel to the shorter lateral sides of the PV module, two parallel strings can be geometrically well integrated into a rectangular PV module. For example, when the PV module has three cell arrangements that are contactable independently of each other, then three times two contacts adjacent to each other are arranged along the neutral line. The contact group with two connection contacts is here located approximately centrally along the center line, while the other two contact groups are located on one side and the other side, respectively, close to the longitudinal edges of the PV module. In this case, according to the above document, each connection region is covered by one box containing a bypass diode. At least two of the cassettes are made to function as junction boxes as previously described by introducing wiring cables for externally connecting the PV modules to each of the cassettes separately and connecting with one of the cell devices within the cassette.

The use of multiple individual cassettes for each cell device results in increased costs in assembly and sealing of the cassettes or cassettes if necessary, as compared to PV modules in which all connection contacts are positioned adjacent to each other and a common junction box is used.

Disclosure of Invention

The object of the application is to provide a junction box and a photovoltaic module having such a junction box, in which the assembly effort is low even for modules in which the contacts of different cell arrangements are not led out of the PV module adjacent to one another.

This object is achieved by a junction box or a PV module having such a junction box with the features of the respective independent claims. Advantageous embodiments and improvements are the subject matter of the dependent claims.

The photovoltaic module according to the application is characterized in that exactly one junction box is arranged on the rear side of the photovoltaic module, which junction box has a housing with at least one opening for passing through the connection contacts towards the rear side, wherein the housing covers all the connection contacts of the photovoltaic module.

The present application is based on the recognition that: by a corresponding design of the housing of the junction box, it is possible and advantageous for the connection contacts of the cell arrangement to be covered by and contacted in a single junction box even for PV modules in which the connection contacts are not located in a common connection region on the back side of the PV module. Accordingly, only this junction box needs to be mounted on the back side of the PV module, which simplifies and speeds up the contacting and manufacturing of the PV module.

Furthermore, the junction box forms a reinforcement and stabilization of the PV module due to its longitudinal extension. The stability provided by the junction box of the PV module can, for example, withstand higher snow or wind loads. Larger PV modules are advantageous in terms of energy efficiency in the production, transportation and assembly of the PV modules. As the size of PV modules becomes larger, the stiffening and stabilizing effects achieved by the present application may become more important in the future. Thus, the robustness provided by the junction boxes extending over all of the contact blocks supports the manufacturability of larger PV modules. In addition to the positive properties of stability and reinforcement during operation, the greater rigidity of the PV module also facilitates handling during production, transport and installation.

In one advantageous embodiment, the PV module has a rectangular base surface, wherein the line along which the connection contacts are arranged extends parallel to one of the lateral edges of the PV module and wherein the length of the housing of the junction box is greater than 50% of the length of the lateral edge, and preferably greater than 66% of the length of the lateral edge. With the housing dimensions, the connection contacts of the PV module can be covered by two or three separate cell arrangements. The length of the junction box is thus an important part of the PV module dimensions, thereby improving the reinforcement effect. The line along which the contacts are connected preferably extends approximately centrally on the back side of the PV module. In this position, it is particularly effective for supporting the layer stack of the photovoltaic module.

In a further advantageous embodiment, the PV module has an outer frame made of metal profiles, wherein the housing of the junction box extends with at least one, preferably both, end sections up to the frame. In this case, in order to further increase the stiffening effect, the junction box is extended beyond the length required for covering the connection contacts of the PV module up to the frame and further up to the edge of the PV module.

In a further advantageous embodiment of the PV module, the housing of the junction box has a bottom surface which serves as an adhesive surface by means of which the junction box is adhered to the rear surface. The longitudinal extension of the housing enables the use of relatively large adhesive surfaces, which results in a high load capacity of the connection between the junction box and the rear side of the photovoltaic module. For example, this prevents the pulling force on the connection cable connected to the terminal box from unintentionally separating the terminal box from the rear face.

The junction box according to the application for a photovoltaic module of the type mentioned at the outset is characterized in that the housing has an elongated basic shape, wherein all the connection contacts are arranged in a line in the longitudinal direction of the housing. Due to this design of the housing, all connection contacts of PV modules of this type of construction can be contacted in the junction box. The advantages set forth in connection with the PV module are obtained.

In an advantageous embodiment of the terminal box, the contacts are arranged in the housing in the contact region. The housing can also have openings in the contact region, each facing upwards, which can be closed by a cover. By means of a corresponding seal, the housing cavity can be hermetically sealed by the cover, so that, for example, it is not necessary to seal the cavity. Advantageously, the contact areas remain accessible by opening the cover and are also easier to separate in case of recycling.

In a further advantageous embodiment, the junction box has at least one contact carrier which carries at least two contacts for contacting the connection contacts of the PV module. The contact carrier may advantageously be formed by a stamped grid. It is also conceivable that the at least one contact carrier carries all contacts for contacting the connection contacts, i.e. that it extends through the housing over all contact areas. For example, a tulip contact may be used as the contact. Furthermore, at least one bypass diode can be arranged on the at least one contact carrier, which bypass diode is connected in parallel with the two contacts. The bypass diode can easily be replaced together with the contact carrier by means of a passage through the cover or covers to the contact carrier in case of failure of one of the bypass diodes.

Drawings

The application is explained in more detail below on the basis of embodiments with the aid of the figures. The drawings show:

figure 1a shows an isometric view of a PV module at its rear view angle;

fig. 1b shows a detail view of the PV module of fig. 1a in the region of a junction box;

figure 2a shows an isometric view of a PV module at its back viewing angle in a second embodiment;

fig. 2b shows a detail view of the PV module of fig. 2a in the region of a junction box;

FIG. 2c shows an isolated isometric view of the junction box according to FIGS. 2a, b from its back side view;

figure 3a shows an isometric view of components of a junction box of a PV module prior to making contact;

figure 3b shows an isometric view of the contact element according to figure 3a at its rear view angle; and figure 3c shows the structure according to figure 3a in a contact state.

List of reference numerals

1. Photovoltaic module (PV module)

2. Frame

3. Back surface

4. Connection contact

10. Wiring device

11. Junction box

111. Shell body

112. Contact area

113. End section

114. Bottom surface

12. Cover

13. Contact element

131. Stamping grille

132. Joint

133. Tulip contact

134. Bypass diode

14. Wiring cable

15. Contact carrier

151. Bottom surface

152. Contact guide groove

Detailed Description

Figure 1a shows a PV module 1 in an isometric view. The PV module 1 has a frame 2 and an actual module structure, which is also referred to as a layer structure or layer stack within the framework of the application. Only the rear side 3 of the module structure can be seen in the illustration of fig. 1 a.

In the PV module 1, the module structure comprises one or more cell arrangements (here in particular three) each having a plurality of PV cells, here not individually identifiable, which are each arranged in the form of two strings. The back side 3 of the PV module 1 is covered with an insulating layer, wherein the insulating layer is interrupted at selected locations to allow the connection contacts of the cell arrangement to be exposed.

Due to the modular structure, in the PV module 1 of fig. 1a, the connection contacts are arranged in groups along the midline of the PV module 1, two connection contacts per group for each cell arrangement. The central line of the PV module 1 runs parallel to its (shorter) lateral sides and centrally with respect to the (longer) longitudinal sides of the PV module 1, the base surface of the PV module being rectangular.

Along the center line, a connection device 10 is provided, which is shown enlarged in fig. 1 b. The junction device 10 includes a junction box 11 and two junction cables 14.

According to the application, the junction box 11 extends in the transverse direction of the PV module 1 over almost the entire dimension of the PV module 1, so that all connection contacts of the PV module 1 are covered by one single junction box 11 and are contacted correspondingly within this junction box 11. The junction box 11 accordingly has a continuous and elongated housing 111. The housing 111 widens and increases in three contact areas 112 (the connection contacts of the PV module 1, which are not visible here, are located in the contact areas 112) and are each covered upward by a cover 12.

In the same way as in fig. 1a and 1b, a further embodiment of a PV module 1 with a wiring device 10 is shown in fig. 2a and 2 b. The configuration of the PV module 1 and the wiring device 10 substantially corresponds to the configuration of the first embodiment. The difference is that, as can be seen in particular from fig. 2b, the junction box 11 is guided to the frame 2 of the PV module 1 by means of two outer contact regions 112 with an extended end section 113.

In both embodiments, the elongated junction box 11 together with the correspondingly shaped housing 111 enables contact to be made by all connection contacts of the PV module 1 by means of a single junction box 11. Accordingly, only this junction box 11 has to be mounted to the back side 3 of the PV module 1. This accelerates the contacting and thus the production of the PV module 1.

Furthermore, the junction box 11 forms a stiffening and stabilizing of the PV module 1 due to its extension over almost the entire width (fig. 1a, 1 b) or the entire width (fig. 2a, 2 b) of the PV module 1. The PV module 1 can be subjected to, for example, greater snow or wind loads due to the stabilization by the junction box 11. In addition to the positive properties of stability and reinforcement during operation, the greater rigidity of the PV module 1 also facilitates handling during production, transport and assembly.

In fig. 2c, the junction device 10, i.e. the junction box 11 and junction cable 14, is shown separately from the PV module 1 in a view towards its bottom side. In this figure, the housing 111 is shown to provide a large adhesive surface on its bottom surface 114, with which the junction box 11 is adhered to the rear surface 3 of the PV module 1 and is thereby also sealed. The large adhesive surface also results in a high load capacity of the connection between the junction box 11 and the rear face 3 of the PV module 1, which prevents, for example, a pulling force on the junction cable 14 from unintentionally detaching the junction box 11 from the rear face 3 of the PV module 1.

It can also be seen in fig. 2c that the housing 111 provides a continuous cavity extending over three contact areas 112. If the contact of the cell devices with each other is not made within the PV module 1, the cavity between the two contact areas 112 present in the housing 111 can be used to make an electrical connection between the connection contacts of different cell devices within the junction box 11.

Fig. 3a-c show the areas of two connection contacts 4 on the back side 3 of the PV module 1, respectively.

In fig. 3a, two connection contacts 4 of the cell arrangement can be seen, which protrude from the rear side 3 of the PV module 1 in the form of connection tabs. On the connection contacts 4, a contact carrier 15 is inserted, which contact carrier 15 is glued with its bottom surface 151 to the rear surface 3 of the PV module 1. In the region of the connection contacts 4, the contact carrier 15 has contact guide grooves 152 which guide the connection contacts 4 and prevent the connection contacts 4 from bending sideways.

In the embodiment shown, one contact carrier 15 is provided per two connection contacts 4. In the PV module 1 shown in fig. 1a to 2c, three contact carriers 15 are used, corresponding to the number of three cell arrangements. In alternative embodiments, it is also possible to use a single elongated contact carrier which extends over the connection areas of all the cell arrangements and accommodates all the connection contacts 4 of the PV module 1, for example by means of a corresponding number of contact guide slots 152.

The housing 111 of the terminal block 11 is then placed onto these or this contact carrier 15, wherein the housing 111 completely encloses the contact carrier 15. As described in connection with fig. 2c, the bottom surface 114 of the housing 111 rests on and adheres to the back surface 3 of the PV module 1.

For contacting each two connection contacts 4 of a cell arrangement, a contact element 13 is provided, which has been inserted into the housing 111. Such a contact element 13 is shown in fig. 3a before being placed on the connection contact 4 or the contact carrier 15. The housing 111 of the terminal block 11 is not shown here, so that the contact carrier 15 and the contact element 13 are visible.

The contact element 13 is designed, for example, on the basis of a stamped grid 131. A joint 132 is formed laterally on the stamped grid 131, wherein one of the wiring cables 14 is fixed to one of the joints 132, for example, by a spot welding process. A connection cable can be connected to the opposite connector 132, which connection cable leads to the next contact region 112. The second connector 132 may also remain open if internal contacts are provided between the cell devices in the PV module 1.

Two contacts for contacting the connecting contact 4, which are designed here as tulip contacts 133, are also provided on the contact element 13. Furthermore, a bypass diode 134 is mounted, which is electrically connected between the two tulip contacts 133, so that it is connected in parallel with the connection contact 4 and thus with the cell arrangement.

In fig. 3b, the contact element 13 is again shown in its bottom view in isolation. In order to be able to mount, in particular to weld or braze, the tulip contact 133 and the bypass diode 134 to the stamped grid 131, the stamped grid 131 is still initially integrated. Thus, the lateral connectors 132 remain initially electrically connected to each other. After the tulip contact 133 and bypass diode 134 are assembled, the connection is split at a split point 135.

The fastening of the mounted contact element 13 in the terminal block 11 can be performed by means of latching elements formed in the housing 111 of the terminal block 11. Alternatively or additionally, a hot stamped holding element of the housing 111 may be used. It is conceivable here for the breaking of the separating point 135 to take place in a working step with hot stamping.

Fig. 3c again shows the structure of fig. 3a in the assembled state, in which the contact element 13 is pressed onto the connection contact 4, so that the tulip contact 133 contacts the connection contact 4.

As already mentioned, the contact element 13 is preferably already integrated into the terminal box 11. Alternatively, as can be seen in fig. 3c, the contact element 13 can also be placed onto the contact carrier 15 first without a terminal box and then the terminal box 11 is covered thereon.

In any case, the cavity formed in the housing 111 of the junction box 11 is hermetically sealed by adhering the junction box 11 with its bottom face 114 to the rear face 3 of the PV module 1 and by closing the contact region 12 with the cover 12, so that, for example, no potting of the cavity is required. Advantageously, the contact element 13 can then be replaced by opening the cover 12, for example when a fault occurs at the associated bypass diode 134. If no component exchange is provided, the cover 12 can also be constructed integrally with the terminal block 11, i.e. the terminal block 11 can be completely closed except for the opening in its bottom face 114.

Claims (13)

1. Photovoltaic module (1) with at least two cell arrangements, which are externally accessible at connection contacts (4), which connection contacts (4) are arranged along a line on the back side of the photovoltaic module (1) to be assigned to groups of two connection contacts (4) of the cell arrangements, characterized in that exactly one junction box (11) is arranged on the back side (3) of the photovoltaic module (1), which junction box has a housing (111) with at least one opening for passing through the connection contacts (4) towards the back side (3), wherein the housing (111) covers all connection contacts (4) of the photovoltaic module (1).

2. Photovoltaic module (1) according to claim 1, having a rectangular base surface, wherein the line along which the connection contacts (4) are arranged extends parallel to one of the lateral edges of the photovoltaic module (1), and wherein the length of the housing (111) of the junction box (11) is greater than 66% of the length of the lateral edge, and preferably greater than 80% of the length of the lateral edge.

3. Photovoltaic module (1) according to claim 2, having an outer frame (2) made of metal profiles, wherein the housing (111) of the junction box (11) extends with at least one end section (113) to the frame (2).

4. A photovoltaic module (1) according to claim 3, wherein the housing (111) of the junction box (11) extends with end sections (113) on both sides to the frame (2).

5. The photovoltaic module (1) according to any one of claims 1 to 4, wherein the housing (111) has a bottom surface (114) serving as an adhesive surface by means of which the junction box (11) is adhered to the back surface (3).

6. Junction box (11) for a photovoltaic module (1) having at least two cell arrangements which are externally accessible at least two connection contacts (4), wherein the junction box (11) has a housing (111) having at least one opening for passing through the connection contacts (4), and wherein at least four contacts for contacting the connection contacts (4) are arranged in the housing (111), characterized in that the housing (111) has an elongated basic shape, wherein all connection contacts (4) are arranged in a line along a longitudinal direction of the housing (111).

7. The junction box (11) according to claim 6, wherein the contacts are arranged in a contact region (112) in a housing (111).

8. Junction box (11) according to claim 7, wherein the housing (111) also has openings in the contact areas (112) upwards, respectively, which openings can be closed by a cover (12).

9. Junction box (11) according to any of claims 6 to 8, having at least one contact carrier (13) carrying at least two contacts.

10. Terminal box (11) according to claim 9, wherein the at least one contact carrier (13) is formed by a stamped grid (131).

11. Junction box (11) according to claim 9 or 10, wherein the at least one contact carrier (13) carries all contacts for contacting the connection contacts (4).

12. Junction box (11) according to any of claims 6 to 11, wherein the contacts are tulip contacts (133).

13. Junction box (11) according to any of claims 9 to 12, wherein at least one bypass diode (134) connected in parallel with two contacts is arranged on the at least one contact carrier (13).